CN113861682A - Inorganic/organic mutually-doped hydrophobic polyimide aerogel and preparation method thereof - Google Patents

Inorganic/organic mutually-doped hydrophobic polyimide aerogel and preparation method thereof Download PDF

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CN113861682A
CN113861682A CN202111264448.0A CN202111264448A CN113861682A CN 113861682 A CN113861682 A CN 113861682A CN 202111264448 A CN202111264448 A CN 202111264448A CN 113861682 A CN113861682 A CN 113861682A
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CN113861682B (en
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郑玉婴
熊立尧
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Fuzhou University
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    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
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    • C08G73/1007—Preparatory processes from tetracarboxylic acids or derivatives and diamines
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    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C08G73/1042—Copolyimides derived from at least two different tetracarboxylic compounds or two different diamino compounds
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    • C08G73/1067—Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
    • C08G73/1071—Wholly aromatic polyimides containing oxygen in the form of ether bonds in the main chain
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Abstract

The invention discloses a preparation method and a performance test of a low-density hydrophobic polyimide aerogel material, which has a more green and convenient preparation process. Diamine monomer and dianhydride monomer are used to synthesize water-soluble polyamic acid precursor. And continuously preparing wet gel from the polyamic acid precursor, and further preparing the polyimide aerogel with hydrophobicity by adopting the processes of freeze drying, thermal amidation and the like. The aerogel prepared by the invention has the characteristics of hydrophobicity, suitability for various molding and pouring processes, simple preparation process, great reduction of organic matter volatilization in the preparation process and the like. In the materialPartially porous, and has a density of less than 0.1g/cm3The water contact angle of the surface of the aerogel can reach more than 120 degrees, and the aerogel has good thermal performance. The method has a large application space in the fields of heat insulation, catalysis, organic matter adsorption, air filtration and the like.

Description

Inorganic/organic mutually-doped hydrophobic polyimide aerogel and preparation method thereof
Technical Field
The invention relates to the field of high-performance aerogel, in particular to inorganic/organic mutually-doped hydrophobic polyimide aerogel and a green preparation method thereof.
Background
Aerogels are a general generic term for a class of solid substances with high porosity and low density. In general, the aerogel has the characteristics of low thermal conductivity and high specific surface area, so that the aerogel can be widely applied to the fields of building heat preservation, equipment and instrument protection and the like. Conventional aerogels are typically inorganic silica aerogels, which are typically prepared using a sol-gel process. But the defects of poor mechanical property and easy powder and slag removal limit the application of the inorganic silicon aerogel in various fields. However, the organic polymer aerogel having more excellent flexibility and the like has limited application fields due to its poor thermal stability.
Polyimides are a class of polymers with high glass transition temperature, high heat loss temperature, abrasion resistance and very high mechanical properties, all of which are structurally characterized by having imide rings. Based on the excellent performance of the polyimide material, a hydrophobic polyimide aerogel material with low density, high heat resistance and high heat insulation can be constructed so as to meet the urgent requirements of the current industrial and scientific research departments on the light/high-heat-performance materials in the industries of heat insulation, oil absorption, fuel cells and the like.
The general aerogel is divided into three processes of wet gel construction and wet gel drying. The most common chemical imidization method for preparing hydrophobic polyimide aerogel at present is to construct a polyamic acid crosslinking system in an organic system, perform imidization treatment on the polyamic acid crosslinking system by chemical reaction of pyridine, acetic anhydride and other substances, and finally apply supercritical CO2The organic system is removed. However, the method has the disadvantages of high cost, complex process, difficulty in adjusting components in the preparation process, long-term contact with harmful organic substances in the environment and human body, and generation of a large amount of Volatile Organic Compounds (VOC). Based on the above problems, there have been some studies to simplify the preparation process requirements, improve the flexibility of the formulation, and avoid harmful organic substances that may occur during imidization and drying processes by constructing a water-soluble polyamic acid precursorObject contact and VOC emission problems, but generally aerogel materials prepared in this way are difficult to have a good hydrophobic character. There are methods for preparing polyamic acid precursor solutions and using acetone as a precipitating agent to prepare polyamic acid precursor powders to increase the hydrophobicity of aerogel products (Xueying He, Li Zhang, depend men, Juntao Wu (2017). From hydrogel to aerogel: a green contamination of multifunctional polyimide precursors From solvents, European Polymer Journal, 89, 461-. However, improving the dispersibility of the doped material is still a subject to be discussed. If the dopant material accumulates during the aerogel production process, stress concentrations or poor contact of the inorganic-organic interface can make the modified aerogel material difficult to form or degrade.
The prepared modified wet gel is added into a polymer system by a liquid-phase mutual dissolving method in the process of preparing the wet gel, so that the phenomenon of nanoparticle aggregation possibly occurring in the traditional doping process is improved. The bridging effect of the carbon quantum dots and the modification of the cobalt-iron oxide system also help the binding force between the modified material and the polymer phase, and further enhance the performance index of the aerogel. The modified carbon quantum dots and the cobalt iron oxide also form a multilayer interface, which is beneficial to improving the overall thermal resistance of the aerogel. Scanning electron micrographs show that no two phases are distinguished in the microstructure, and an inorganic system and an organic system are uniformly dispersed in the system to form an inorganic/organic mutual doping microstructure, so that the skeleton structure of the aerogel is formed. Tests prove that the hydrophobic polyimide aerogel with low density, high heat insulation and high heat resistance is prepared.
Disclosure of Invention
The invention aims to provide a green method for preparing polyimide aerogel, which can be applied to industrial processing technology, is widely tried out, has simple preparation process and good dispersion compatibility of a doping material. By improving the preparation and precipitation processes of the polyamic acid precursor, the solvent replacement process required by the traditional aerogel material preparation is completely abandoned, and the use and volatilization of the organic solvent in the preparation process are greatly reduced, so that the microstructure of the aerogel material is kept. The modified carbon quantum dots are used as bridges, organic phases and inorganic phases are combined with each other in a water system, and a wet gel system which is compatible and has good dispersibility is constructed. Meanwhile, a more convenient and fast freeze drying process is adopted in the drying process, compared with supercritical drying, the processing process is simplified, and the processing cost is reduced.
The invention provides an inorganic/organic mutually-doped hydrophobic polyimide aerogel and a green preparation method thereof.
Modified carbon quantum dots, a polyamic acid precursor and a cobalt-iron oxide inorganic gel liquid-phase system are used as raw materials, and a mutually-doped polyimide aerogel system with an inorganic/organic part serving as a framework is constructed.
Briefly, the present invention is realized by the following method:
a preparation method of an inorganic/organic intermingled hydrophobic polyimide aerogel comprises the following steps:
1) reacting a diamine monomer and a dianhydride monomer in an organic solvent at low temperature to obtain a viscous yellow polyamic acid solution;
2) reacting the polyamic acid solution with a quaternization reactant, slowly adding the reaction product into deionized water at a low temperature for precipitation, washing with the deionized water until the organic solvent is completely removed, and drying the obtained product to obtain a polyamic acid water-soluble precursor;
3) dissolving the polyamic acid water-soluble precursor in 0.5-2.5 wt% of modified carbon quantum dot deionized water solution, slowly adding the solution into a cobalt-iron oxide inorganic gel liquid phase system for several times, pre-freezing and freeze-drying to obtain polyamic acid aerogel;
4) and carrying out thermal imidization treatment on the polyamic acid aerogel in an inert atmosphere to obtain the inorganic/organic mutually-doped hydrophobic polyimide aerogel composite material.
Preferably, the low-temperature environment in the step 1) is-1-4 ℃; specifically, the diamine monomer is one or more of 3,4 '-diaminodiphenyl ether, 4' -diaminodiphenyl ether, 2- (4-aminophenyl) -5-aminobenzimidazole, and 2,2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl. The dianhydride monomer is one or more of 1,2,4, 5-pyromellitic dianhydride, 3,3' -biphenyl tetracarboxylic dianhydride, 3,3',4,4' -triphenyl diether tetracarboxylic dianhydride and maleic anhydride. The molar ratio of the total molar amount of diamine monomer to the total molar amount of dianhydride monomer is one of 100:101, 50:51, and 20: 21. The organic solvent is one or more of N, N-dimethylformamide, N-dimethylacetamide, methanol, dimethylethanolamine and ethanol. The mass ratio of the total mass of the diamine monomer and the dianhydride monomer to the mass of the organic solvent is 1: 8-15.
Preferably, the quaternizing reagent in the step 2) is one or more of triethylamine, N-methyldiethanolamine and pyridine. The molar ratio of the molar amount of the quaternization reactant to the molar amount of the dianhydride monomer is 1: 0.5-2. The low temperature is specifically 0-5 ℃. The ratio of the polyamic acid solution to deionized water for precipitation is 1: 10-20, and the washing times are more than four times or until the precipitation is completely converted into a white solid. And the product drying is specifically to pre-freeze and freeze-dry the product to obtain a white polyamic acid water-soluble precursor. Specifically, the prefreezing temperature is lower than-5 deg.C, and the freeze drying time is not less than 12 hr.
Preferably, the modified carbon quantum dots are dissolved in deionized water by any method such as stirring/ultrasonic dispersion, the polyamic acid water-soluble precursor is added, stirred and dissolved until the system is uniform, and the polyamic acid water-soluble precursor is slowly added into the cobalt-iron oxide inorganic gel liquid phase system in batches. Prefreezing at least-10 deg.C, and freeze drying the solid product in a freeze dryer to obtain polyamic acid aerogel.
Preferably, the thermal imidization treatment is a multi-stage thermal treatment mode, and the thermal insulation time and the heating rate are modified, so that each stage of the formation of the aerogel chemical structure can be fully completed at each designed temperature stage, and the mutual competition of reactions and the damage of overhigh reaction temperature to the aerogel chemical structure are avoided. The aerogels are formed in particular by:
the first stage is heating from room temperature to 75 deg.C, 85 deg.C or 95 deg.C at a heating rate of 2 deg.C, 3 deg.C, 4 deg.C or 5 deg.C/min; generally speaking, heating the mixture from room temperature to 75-95 ℃ at a heating rate of 2-5 ℃/min;
the second stage is heating from room temperature to 100 deg.C, 110 deg.C or 120 deg.C at a heating rate of 0.5 deg.C, 1 deg.C, 2 deg.C or 3 deg.C/min; generally speaking, heating to 100-120 ℃ at a heating rate of 0.5-3 ℃/min;
the third stage is heat preservation at 100 ℃, 110 ℃ or 120 ℃ for 40 minutes, 60 minutes, 90 minutes or 120 minutes; generally speaking, the temperature is kept at 100-120 ℃ for 40-120 minutes;
the fourth stage is heating from 100 deg.C, 110 deg.C or 120 deg.C to 170 deg.C, 190 deg.C or 210 deg.C at a heating rate of 1 deg.C, 2 deg.C, 3 deg.C or 4 deg.C/min; generally speaking, heating the mixture from 100 to 120 ℃ to 170 to 210 ℃ at a heating rate of 1 to 4 ℃/min;
the fifth stage is heat preservation at 170 ℃, 190 ℃ or 210 ℃ for 60 minutes, 100 minutes or 130 minutes; in general, in the experimental example, the temperature is kept at 170-210 ℃ for 60-130 minutes;
the sixth stage is heating from 170 deg.C, 190 deg.C or 210 deg.C to 280 deg.C, 300 deg.C or 320 deg.C at a heating rate of 1 deg.C, 2 deg.C or 3 deg.C/min; generally speaking, heating from 170-210 ℃ to 280-320 ℃ at a heating rate of 1-3 ℃/min;
the seventh stage is heat preservation at 280 deg.C, 300 deg.C or 320 deg.C for 40 min, 60 min or 80 min; generally speaking, the temperature is kept for 40 to 80 minutes at the temperature of 280 to 320 ℃;
the eighth stage is to cool the temperature from 280 ℃, 300 ℃ or 320 ℃ to the room temperature at the cooling rate of 2 ℃,3 ℃ or 4 ℃/min; generally speaking, the temperature is reduced from 280 ℃ to 320 ℃ to the room temperature at the cooling rate of 2-4 ℃/min.
The cobalt iron oxide inorganic gel is obtained by hydrolyzing inorganic metal salt in a water system. The modified inorganic gel has the advantages of simple and convenient preparation and high dispersibility in a water phase. The introduced carbon quantum dots are used as bridges to perform hydrogen bond crosslinking and chemical bond combination between the inorganic gel system and the organic gel system. Hydrogen bonding crosslinks and chemical bonding helps promote compatibility of the two phases in the aerogel, thereby further promoting the mechanical and thermal stability of the aerogel. Meanwhile, the modified inorganic framework is beneficial to controlling the growth of ice crystals and the collapse of a microstructure and the integral contraction of aerogel in the freezing and freeze-drying processes and the heat treatment processes, and plays roles in adjusting the pore size and protecting the aerogel structure. The simplified inorganic gel modification method and the addition mode greatly reduce the influence of the modified formula on the production and processing technology of aerogel products.
Further, the preparation method provided by the application also comprises the following steps.
The preparation process of the modified carbon quantum dot comprises the following steps:
(a) ultrasonically dispersing common graphene oxide in 50mL of deionized water, and mutually dissolving the graphene oxide and an amino modifier aqueous solution;
(b) placing the graphene oxide/amino modifier water dispersion system in a polytetrafluoroethylene hydrothermal reaction kettle to carry out hydrothermal reaction for 4-16 hours at 80 ℃;
(c) and (3) carrying out suction filtration on the obtained modified carbon quantum dot sol, heating the filtrate at 100 ℃ for 1 hour, placing the filtrate in a dialysis membrane for dialysis for 4-7 days, and freeze-drying the product to obtain the amino modified carbon quantum dot.
Preferably, the amino modifier is one or more of ammonia water, ethylenediamine and triethylene tetramine.
The preparation method of the cobalt-iron oxide inorganic gel liquid phase system comprises the following steps: dissolving quantitative ferric chloride and cobalt acetate in deionized water, and then gradually adjusting the pH value to 8.5 by using triethylamine under a pH meter to obtain a cobalt-iron oxide inorganic gel liquid-phase system.
Preferably, the mass fraction of the ferric chloride and the cobalt acetate is 1: 2-5; the mass ratio of the sum of the mass of ferric chloride and cobalt acetate to the mass of deionized water is 1: 20-250.
Drawings
FIG. 1 is a scanning electron microscope image of a polyimide aerogel prepared in example 1 of the present invention;
FIG. 2 is a water contact angle image of example 1 of the present invention;
FIG. 3 is the thermogravimetric measurement of example 1 of the present invention, conducted at room temperature to 800 deg.C under argon atmosphere.
Detailed Description
The present invention is further illustrated by the following examples in which the technical requirements and embodiments of the invention are best understood and described in an effort to be fully and clearly understood. The instruments, equipments and reagents mentioned in the examples are all conventional pure products commercially available, and the parts of the examples where no specific conditions are noted are all conventional conditions, the conditions experienced by the general experimenters, the conditions suggested by the experimental instruments and equipments or the knowledge and technology recognized by those skilled in the art. The process can be adjusted by those skilled in the art according to actual production, processing, etc. The following examples do not limit the scope of protection described in the present invention.
Example 1
The embodiment provides an inorganic/organic intermingled hydrophobic polyimide aerogel and a green preparation method, and the method comprises the following steps:
1) preparation of polyamic acid solution: 2.436g of 4,4 '-diaminodiphenyl ether and 2.436g of 3,4' -diaminodiphenyl ether are dissolved in 80mL of N, N-dimethylacetamide at the temperature of 5 ℃, and 5.128g of 1,2,4, 5-pyromellitic dianhydride is slowly added after the solution is stable, uniform and transparent. The reaction was stirred for 3 hours to give a pale yellow, transparent and viscous polyamic acid solution.
2) Preparation of polyamic acid precursor: at the temperature of 5 ℃, light yellow transparent viscous polyamic acid solution and 2.46g triethylamine are uniformly mixed and stirred for 1.5 hours, and transparent viscous uniform polyamic acid precursor sol is obtained. And slowly adding the polyamic acid precursor sol into 1L of deionized water to obtain white polyamic acid precursor precipitate, and washing the precipitate with the deionized water for five times until the organic phase is completely removed. The white precipitate was then prefreezed in a refrigerator at-5 ℃ and lyophilized for 12 hours to yield a goose-yellow polyamic acid precursor powder.
3) Preparing modified carbon quantum dots: dispersing 5gGO in 50mL of water, gradually dropwise adding 80mL of 10% mass fraction concentrated ammonia water while stirring, placing the mixture in a polytetrafluoroethylene high-pressure hydrothermal reaction kettle, and reacting for 6 hours at the constant temperature of 80 ℃. And carrying out suction filtration on the obtained modified carbon quantum dot sol, and heating the filtrate to 100 ℃ and keeping the temperature for 1 hour. After cooling, the product was placed in a dialysis membrane and dialyzed for 5 days. Amino-modified carbon quantum dots obtained by reducing and shearing graphene oxide were obtained after freeze-drying for 48 hours.
4) Preparing a cobalt iron oxide inorganic gel liquid phase system: 0.05g of FeCl3And 0.1g of cobalt acetate are dissolved in 10mL of deionized water, the mixture is stirred for 5 minutes or until the solution is uniform, and the pH value of the system is adjusted to 8.5 by dropwise adding a small amount of triethylamine and the mixture is stirred for 30 minutes to fully hydrolyze the system.
5) Preparation of polyamic acid aerogel: 0.05g of modified carbon quantum dots are dissolved and dispersed in 10mL of deionized water through 5min of ultrasonic treatment, and 1g of polyamic acid precursor is added into the system and stirred for 2 hours to obtain transparent and viscous polyamic acid sol. The transparent and viscous polyamic acid sol is divided into five batches to be mixed with the cobalt iron oxide inorganic gel liquid phase system, and the final system is ensured to be uniformly mixed each time of mixing. The obtained transparent polyamic acid wet gel is placed in a refrigerator at-15 ℃ for pre-freezing and aging until the wet gel is completely solidified and kept at a constant temperature. The solid was freeze-dried in a freeze-dryer for 12 hours to obtain a white polyamic acid aerogel.
6) The preparation method of the polyimide aerogel comprises the following steps: the first section is heated to 85 ℃ at the heating rate of 2 ℃/min, the second section is heated from 85 ℃ to 110 ℃ at the heating rate of 1 ℃/min, the third section is kept at 110 ℃ for 60 min, the fourth section is heated from 110 ℃ to 190 ℃ at the heating rate of 4 ℃/min, the fifth section is kept at 190 ℃ for 100 min, the sixth section is heated from 190 ℃ to 320 ℃ at the heating rate of 2 ℃/min, the seventh section is kept at 320 ℃ for 40 min, and the eighth section is cooled from 320 ℃ to room temperature at the cooling rate of 3 ℃/min. Finally obtaining the dark yellow flexible polyimide aerogel.
Scanning electron microscope images of the polyimide aerogel obtained in example 1 are shown in fig. 1, and it can be seen that the aerogel is filled with a regular and uniform micro-pore structure. The microstructure does not have the aggregation of the doped phase, so that the microstructure with inorganic/organic mutual doping, uniform dispersion and mutual compatibility is proved to be formed, and the inorganic part and the organic part jointly form the framework structure of the aerogel.
The water contact angle image of the polyimide aerogel obtained in example 1 is shown in fig. 2, and it can be seen that the aerogel has a water contact angle of > 130 ° and has good hydrophobicity.
The thermogravimetric measurement result of the polyimide aerogel obtained in example 1 is shown in fig. 3, and the aerogel has extremely high heat loss temperature (> 500 ℃), and can still maintain a stable state under an extremely hot environment.
Example 2
This example provides an inorganic/organic intermingled hydrophobic polyimide aerogel and a green preparation method, the preparation process is basically the same as that of example 1, only carbon quantum dots are not added to play a contrast role, and the method comprises the following steps:
1) preparation of polyamic acid solution: 2.436g of 4,4 '-diaminodiphenyl ether and 2.436g of 3,4' -diaminodiphenyl ether are dissolved in 80mL of N, N-dimethylacetamide at the temperature of 5 ℃, and 5.128g of 1,2,4, 5-pyromellitic dianhydride is slowly added after the solution is stable, uniform and transparent. The reaction was stirred for 3 hours to give a pale yellow, transparent and viscous polyamic acid solution.
2) Preparation of polyamic acid precursor: at the temperature of 5 ℃, light yellow transparent viscous polyamic acid solution and 2.46g triethylamine are uniformly mixed and stirred for 1.5 hours, and transparent viscous uniform polyamic acid precursor sol is obtained. And slowly adding the polyamic acid precursor sol into 1L of deionized water to obtain white polyamic acid precursor precipitate, and washing the precipitate with the deionized water for five times until the organic phase is completely removed. The white precipitate was then prefreezed in a refrigerator at-5 ℃ and lyophilized for 12 hours to yield a goose-yellow polyamic acid precursor powder.
3) Preparing a cobalt iron oxide inorganic gel liquid phase system: 0.05g of FeCl3And 0.1g of cobalt acetateDissolving in 10mL of deionized water, stirring for 5 minutes or until the solution is uniform, adjusting the pH value of the system to 8.5 by dropwise adding a small amount of triethylamine, and stirring for 30 minutes to fully hydrolyze the system.
4) Preparation of polyamic acid aerogel: 1g of polyamic acid precursor was added to 10mL of deionized water and stirred for 2 hours to give a clear and viscous polyamic acid gel. The transparent and viscous polyamic acid sol is divided into five batches to be mixed with the cobalt iron oxide inorganic gel liquid phase system, and the final system is ensured to be uniformly mixed each time of mixing. The obtained transparent polyamic acid wet gel is placed in a refrigerator at-15 ℃ for pre-freezing and aging until the wet gel is completely solidified and kept at a constant temperature. The solid was freeze-dried in a freeze-dryer for 12 hours to obtain a white polyamic acid aerogel.
5) The preparation method of the polyimide aerogel comprises the following steps: the first section is heated to 85 ℃ at the heating rate of 2 ℃/min, the second section is heated from 85 ℃ to 110 ℃ at the heating rate of 1 ℃/min, the third section is kept at 110 ℃ for 60 min, the fourth section is heated from 110 ℃ to 190 ℃ at the heating rate of 4 ℃/min, the fifth section is kept at 190 ℃ for 100 min, the sixth section is heated from 190 ℃ to 320 ℃ at the heating rate of 2 ℃/min, the seventh section is kept at 320 ℃ for 40 min, and the eighth section is cooled from 320 ℃ to room temperature at the cooling rate of 3 ℃/min. Finally, yellow flexible polyimide aerogel is obtained.
Example 3
This example provides a polyimide aerogel and a green preparation method, the preparation process is substantially the same as that of example 1, only cobalt iron oxide inorganic gel is not added as a comparison, and the method comprises the following steps:
1) preparation of polyamic acid solution: 2.436g of 4,4 '-diaminodiphenyl ether and 2.436g of 3,4' -diaminodiphenyl ether are dissolved in 80mL of N, N-dimethylacetamide at the temperature of 5 ℃, and 5.128g of 1,2,4, 5-pyromellitic dianhydride is slowly added after the solution is stable, uniform and transparent. The reaction was stirred for 3 hours to give a pale yellow, transparent and viscous polyamic acid solution.
2) Preparation of polyamic acid precursor: at the temperature of 5 ℃, light yellow transparent viscous polyamic acid solution and 2.46g triethylamine are uniformly mixed and stirred for 1.5 hours, and transparent viscous uniform polyamic acid precursor sol is obtained. And slowly adding the polyamic acid precursor sol into 1L of deionized water to obtain white polyamic acid precursor precipitate, and washing the precipitate with the deionized water for five times until the organic phase is completely removed. The white precipitate was then prefreezed in a refrigerator at-5 ℃ and lyophilized for 12 hours to yield a goose-yellow polyamic acid precursor powder.
3) Preparing modified carbon quantum dots: dispersing 5gGO in 50mL of water, gradually dropwise adding 80mL of 10% mass fraction concentrated ammonia water while stirring, placing the mixture in a polytetrafluoroethylene high-pressure hydrothermal reaction kettle, and reacting for 6 hours at the constant temperature of 80 ℃. And carrying out suction filtration on the obtained modified carbon quantum dot sol, and heating the filtrate to 100 ℃ and keeping the temperature for 1 hour. After cooling, the product was placed in a dialysis membrane and dialyzed for 5 days. Amino-modified carbon quantum dots obtained by reducing and shearing graphene oxide were obtained after freeze-drying for 48 hours.
4) Preparation of polyamic acid aerogel: 0.05g of modified carbon quantum dots are dissolved and dispersed in 10mL of deionized water through 5min of ultrasonic treatment, and 1g of polyamic acid precursor is added into the system and stirred for 2 hours to obtain transparent and viscous polyamic acid sol. The clear viscous polyamic acid sol was divided into five batches and mixed with 10mL of deionized water, each time to ensure that the final system was mixed well. The obtained transparent polyamic acid wet gel is placed in a refrigerator at-15 ℃ for pre-freezing and aging until the wet gel is completely solidified and kept at a constant temperature. The solid was freeze-dried in a freeze-dryer for 12 hours to obtain a white polyamic acid aerogel.
5) The preparation method of the polyimide aerogel comprises the following steps: the first section is heated to 85 ℃ at the heating rate of 2 ℃/min, the second section is heated from 85 ℃ to 110 ℃ at the heating rate of 1 ℃/min, the third section is kept at 110 ℃ for 60 min, the fourth section is heated from 110 ℃ to 190 ℃ at the heating rate of 4 ℃/min, the fifth section is kept at 190 ℃ for 100 min, the sixth section is heated from 190 ℃ to 320 ℃ at the heating rate of 2 ℃/min, the seventh section is kept at 320 ℃ for 40 min, and the eighth section is cooled from 320 ℃ to room temperature at the cooling rate of 3 ℃/min. Finally obtaining the dark yellow flexible polyimide aerogel.
Example 4
This example provides an inorganic/organic intermingled hydrophobic polyimide aerogel and a green preparation method, the preparation process is basically the same as that of example 1, only the content of inorganic gel is increased for comparison, and the method includes the following steps:
1) preparation of polyamic acid solution: 2.436g of 4,4 '-diaminodiphenyl ether and 2.436g of 3,4' -diaminodiphenyl ether are dissolved in 80mL of N, N-dimethylacetamide at the temperature of 5 ℃, and 5.128g of 1,2,4, 5-pyromellitic dianhydride is slowly added after the solution is stable, uniform and transparent. The reaction was stirred for 3 hours to give a pale yellow, transparent and viscous polyamic acid solution.
2) Preparation of polyamic acid precursor: at the temperature of 5 ℃, light yellow transparent viscous polyamic acid solution and 2.46g triethylamine are uniformly mixed and stirred for 1.5 hours, and transparent viscous uniform polyamic acid precursor sol is obtained. And slowly adding the polyamic acid precursor sol into 1L of deionized water to obtain white polyamic acid precursor precipitate, and washing the precipitate with the deionized water for five times until the organic phase is completely removed. The white precipitate was then prefreezed in a refrigerator at-5 ℃ and lyophilized for 12 hours to yield a goose-yellow polyamic acid precursor powder.
3) Preparing modified carbon quantum dots: dispersing 5gGO in 50mL of water, gradually dropwise adding 80mL of 10% mass fraction concentrated ammonia water while stirring, placing the mixture in a polytetrafluoroethylene high-pressure hydrothermal reaction kettle, and reacting for 6 hours at the constant temperature of 80 ℃. And carrying out suction filtration on the obtained modified carbon quantum dot sol, and heating the filtrate to 100 ℃ and keeping the temperature for 1 hour. After cooling, the product was placed in a dialysis membrane and dialyzed for 5 days. Amino-modified carbon quantum dots obtained by reducing and shearing graphene oxide were obtained after freeze-drying for 48 hours.
4) Preparing a cobalt iron oxide inorganic gel liquid phase system: 0.08g of FeCl3And 0.2g of cobalt acetate are dissolved in 10mL of deionized water, the mixture is stirred for 5 minutes or until the solution is uniform, and the pH value of the system is adjusted to 8.5 by dropwise adding a small amount of triethylamine and the mixture is stirred for 30 minutes to fully hydrolyze the system.
5) Preparation of polyamic acid aerogel: 0.05g of modified carbon quantum dots are dissolved and dispersed in 10mL of deionized water through 5min of ultrasonic treatment, and 1g of polyamic acid precursor is added into the system and stirred for 2 hours to obtain transparent and viscous polyamic acid sol. The transparent and viscous polyamic acid sol is divided into five batches to be mixed with the cobalt iron oxide inorganic gel liquid phase system, and the final system is ensured to be uniformly mixed each time of mixing. The obtained transparent polyamic acid wet gel is placed in a refrigerator at-15 ℃ for pre-freezing and aging until the wet gel is completely solidified and kept at a constant temperature. The solid was freeze-dried in a freeze-dryer for 12 hours to obtain a white polyamic acid aerogel.
6) The preparation method of the polyimide aerogel comprises the following steps: the first section is heated to 85 ℃ at the heating rate of 2 ℃/min, the second section is heated from 85 ℃ to 110 ℃ at the heating rate of 1 ℃/min, the third section is kept at 110 ℃ for 60 min, the fourth section is heated from 110 ℃ to 190 ℃ at the heating rate of 4 ℃/min, the fifth section is kept at 190 ℃ for 100 min, the sixth section is heated from 190 ℃ to 320 ℃ at the heating rate of 2 ℃/min, the seventh section is kept at 320 ℃ for 40 min, and the eighth section is cooled from 320 ℃ to room temperature at the cooling rate of 3 ℃/min. Finally obtaining the black flexible polyimide aerogel.
Example 5
This example provides an inorganic/organic intermingled hydrophobic polyimide aerogel and a green preparation method, the preparation process is basically the same as that of example 1, only the content of inorganic gel is reduced for comparison, and the method comprises the following steps:
1) preparation of polyamic acid solution: 2.436g of 4,4 '-diaminodiphenyl ether and 2.436g of 3,4' -diaminodiphenyl ether are dissolved in 80mL of N, N-dimethylacetamide at the temperature of 5 ℃, and 5.128g of 1,2,4, 5-pyromellitic dianhydride is slowly added after the solution is stable, uniform and transparent. The reaction was stirred for 3 hours to give a pale yellow, transparent and viscous polyamic acid solution.
2) Preparation of polyamic acid precursor: at the temperature of 5 ℃, light yellow transparent viscous polyamic acid solution and 2.46g triethylamine are uniformly mixed and stirred for 1.5 hours, and transparent viscous uniform polyamic acid precursor sol is obtained. And slowly adding the polyamic acid precursor sol into 1L of deionized water to obtain white polyamic acid precursor precipitate, and washing the precipitate with the deionized water for five times until the organic phase is completely removed. The white precipitate was then prefreezed in a refrigerator at-5 ℃ and lyophilized for 12 hours to yield a goose-yellow polyamic acid precursor powder.
3) Preparing modified carbon quantum dots: dispersing 5gGO in 50mL of water, gradually dropwise adding 80mL of 10% mass fraction concentrated ammonia water while stirring, placing the mixture in a polytetrafluoroethylene high-pressure hydrothermal reaction kettle, and reacting for 6 hours at the constant temperature of 80 ℃. And carrying out suction filtration on the obtained modified carbon quantum dot sol, and heating the filtrate to 100 ℃ and keeping the temperature for 1 hour. After cooling, the product was placed in a dialysis membrane and dialyzed for 5 days. Amino-modified carbon quantum dots obtained by reducing and shearing graphene oxide were obtained after freeze-drying for 48 hours.
4) Preparing a cobalt iron oxide inorganic gel liquid phase system: 0.02g of FeCl3And 0.05g of cobalt acetate are dissolved in 10mL of deionized water, the mixture is stirred for 5 minutes or until the solution is uniform, and the pH value of the system is adjusted to 8.5 by dropwise adding a trace amount of triethylamine and the mixture is stirred for 30 minutes to fully hydrolyze the system.
5) Preparation of polyamic acid aerogel: 0.05g of modified carbon quantum dots are dissolved and dispersed in 10mL of deionized water through 5min of ultrasonic treatment, and 1g of polyamic acid precursor is added into the system and stirred for 2 hours to obtain transparent and viscous polyamic acid sol. The transparent and viscous polyamic acid sol is divided into five batches to be mixed with the cobalt iron oxide inorganic gel liquid phase system, and the final system is ensured to be uniformly mixed each time of mixing. The obtained transparent polyamic acid wet gel is placed in a refrigerator at-15 ℃ for pre-freezing and aging until the wet gel is completely solidified and kept at a constant temperature. The solid was freeze-dried in a freeze-dryer for 12 hours to obtain a white polyamic acid aerogel.
6) The preparation method of the polyimide aerogel comprises the following steps: the first section is heated to 85 ℃ at the heating rate of 2 ℃/min, the second section is heated from 85 ℃ to 110 ℃ at the heating rate of 1 ℃/min, the third section is kept at 110 ℃ for 60 min, the fourth section is heated from 110 ℃ to 190 ℃ at the heating rate of 4 ℃/min, the fifth section is kept at 190 ℃ for 100 min, the sixth section is heated from 190 ℃ to 320 ℃ at the heating rate of 2 ℃/min, the seventh section is kept at 320 ℃ for 40 min, and the eighth section is cooled from 320 ℃ to room temperature at the cooling rate of 3 ℃/min. Finally, yellow flexible polyimide aerogel is obtained.
Example 6
This example provides an inorganic/organic intermingled hydrophobic polyimide aerogel and a green preparation method, the preparation process is basically the same as that of example 1, only the organogel content is increased for comparison, and the method comprises the following steps:
1) preparation of polyamic acid solution: 2.436g of 4,4 '-diaminodiphenyl ether and 2.436g of 3,4' -diaminodiphenyl ether are dissolved in 80mL of N, N-dimethylacetamide at the temperature of 5 ℃, and 5.128g of 1,2,4, 5-pyromellitic dianhydride is slowly added after the solution is stable, uniform and transparent. The reaction was stirred for 3 hours to give a pale yellow, transparent and viscous polyamic acid solution.
2) Preparation of polyamic acid precursor: at the temperature of 5 ℃, light yellow transparent viscous polyamic acid solution and 2.46g triethylamine are uniformly mixed and stirred for 1.5 hours, and transparent viscous uniform polyamic acid precursor sol is obtained. And slowly adding the polyamic acid precursor sol into 1L of deionized water to obtain white polyamic acid precursor precipitate, and washing the precipitate with the deionized water for five times until the organic phase is completely removed. The white precipitate was then prefreezed in a refrigerator at-5 ℃ and lyophilized for 12 hours to yield a goose-yellow polyamic acid precursor powder.
3) Preparing modified carbon quantum dots: dispersing 5gGO in 50mL of water, gradually dropwise adding 80mL of 10% mass fraction concentrated ammonia water while stirring, placing the mixture in a polytetrafluoroethylene high-pressure hydrothermal reaction kettle, and reacting for 6 hours at the constant temperature of 80 ℃. And carrying out suction filtration on the obtained modified carbon quantum dot sol, and heating the filtrate to 100 ℃ and keeping the temperature for 1 hour. After cooling, the product was placed in a dialysis membrane and dialyzed for 5 days. Amino-modified carbon quantum dots obtained by reducing and shearing graphene oxide were obtained after freeze-drying for 48 hours.
4) Preparing a cobalt iron oxide inorganic gel liquid phase system: 0.05g of FeCl3And 0.1g of cobalt acetate in 10mL of deionized water, stirring for 5 minutes or until the solution is homogeneous, passing a trace amount ofTriethylamine is added dropwise to adjust the pH value of the system to 8.5 and the system is stirred for 30 minutes to be fully hydrolyzed.
5) Preparation of polyamic acid aerogel: 0.05g of modified carbon quantum dots are dissolved and dispersed in 10mL of deionized water through 5min of ultrasonic treatment, and then 1.5g of polyamic acid precursor is added into the system and stirred for 2 hours to obtain transparent and viscous polyamic acid sol. The transparent and viscous polyamic acid sol is divided into five batches to be mixed with the cobalt iron oxide inorganic gel liquid phase system, and the final system is ensured to be uniformly mixed each time of mixing. The obtained transparent polyamic acid wet gel is placed in a refrigerator at-15 ℃ for pre-freezing and aging until the wet gel is completely solidified and kept at a constant temperature. The solid was freeze-dried in a freeze-dryer for 12 hours to obtain a white polyamic acid aerogel.
6) The preparation method of the polyimide aerogel comprises the following steps: the first section is heated to 85 ℃ at the heating rate of 2 ℃/min, the second section is heated from 85 ℃ to 110 ℃ at the heating rate of 1 ℃/min, the third section is kept at 110 ℃ for 60 min, the fourth section is heated from 110 ℃ to 190 ℃ at the heating rate of 4 ℃/min, the fifth section is kept at 190 ℃ for 100 min, the sixth section is heated from 190 ℃ to 320 ℃ at the heating rate of 2 ℃/min, the seventh section is kept at 320 ℃ for 40 min, and the eighth section is cooled from 320 ℃ to room temperature at the cooling rate of 3 ℃/min. Finally obtaining the dark yellow flexible polyimide aerogel.
Example 7
This example provides an inorganic/organic intermingled hydrophobic polyimide aerogel and a green preparation method, the preparation process is basically the same as that of example 1, only the organogel content is reduced for comparison, and the method comprises the following steps:
1) preparation of polyamic acid solution: 2.436g of 4,4 '-diaminodiphenyl ether and 2.436g of 3,4' -diaminodiphenyl ether are dissolved in 80mL of N, N-dimethylacetamide at the temperature of 5 ℃, and 5.128g of 1,2,4, 5-pyromellitic dianhydride is slowly added after the solution is stable, uniform and transparent. The reaction was stirred for 3 hours to give a pale yellow, transparent and viscous polyamic acid solution.
2) Preparation of polyamic acid precursor: at the temperature of 5 ℃, light yellow transparent viscous polyamic acid solution and 2.46g triethylamine are uniformly mixed and stirred for 1.5 hours, and transparent viscous uniform polyamic acid precursor sol is obtained. And slowly adding the polyamic acid precursor sol into 1L of deionized water to obtain white polyamic acid precursor precipitate, and washing the precipitate with the deionized water for five times until the organic phase is completely removed. The white precipitate was then prefreezed in a refrigerator at-5 ℃ and lyophilized for 12 hours to yield a goose-yellow polyamic acid precursor powder.
3) Preparing modified carbon quantum dots: dispersing 5gGO in 50mL of water, gradually dropwise adding 80mL of 10% mass fraction concentrated ammonia water while stirring, placing the mixture in a polytetrafluoroethylene high-pressure hydrothermal reaction kettle, and reacting for 6 hours at the constant temperature of 80 ℃. And carrying out suction filtration on the obtained modified carbon quantum dot sol, and heating the filtrate to 100 ℃ and keeping the temperature for 1 hour. After cooling, the product was placed in a dialysis membrane and dialyzed for 5 days. Amino-modified carbon quantum dots obtained by reducing and shearing graphene oxide were obtained after freeze-drying for 48 hours.
4) Preparing a cobalt iron oxide inorganic gel liquid phase system: 0.05g of FeCl3And 0.1g of cobalt acetate are dissolved in 10mL of deionized water, the mixture is stirred for 5 minutes or until the solution is uniform, and the pH value of the system is adjusted to 8.5 by dropwise adding a small amount of triethylamine and the mixture is stirred for 30 minutes to fully hydrolyze the system.
5) Preparation of polyamic acid aerogel: 0.05g of modified carbon quantum dots are dissolved and dispersed in 10mL of deionized water through 5min of ultrasonic treatment, and then 0.5g of polyamic acid precursor is added into the system and stirred for 2 hours to obtain transparent and viscous polyamic acid sol. The transparent and viscous polyamic acid sol is divided into five batches to be mixed with the cobalt iron oxide inorganic gel liquid phase system, and the final system is ensured to be uniformly mixed each time of mixing. The obtained transparent polyamic acid wet gel is placed in a refrigerator at-15 ℃ for pre-freezing and aging until the wet gel is completely solidified and kept at a constant temperature. The solid was freeze-dried in a freeze-dryer for 12 hours to obtain a white polyamic acid aerogel.
6) The preparation method of the polyimide aerogel comprises the following steps: the first section is heated to 85 ℃ at the heating rate of 2 ℃/min, the second section is heated from 85 ℃ to 110 ℃ at the heating rate of 1 ℃/min, the third section is kept at 110 ℃ for 60 min, the fourth section is heated from 110 ℃ to 190 ℃ at the heating rate of 4 ℃/min, the fifth section is kept at 190 ℃ for 100 min, the sixth section is heated from 190 ℃ to 320 ℃ at the heating rate of 2 ℃/min, the seventh section is kept at 320 ℃ for 40 min, and the eighth section is cooled from 320 ℃ to room temperature at the cooling rate of 3 ℃/min. Finally obtaining the dark yellow flexible polyimide aerogel.
The results of performance tests including density measurement, water contact angle measurement, and thermal conductivity measurement performed on examples 1 to 7 are shown in table 1.
Figure 443875DEST_PATH_IMAGE002
Example 1 exhibited the best density, contact angle and thermal conductivity/resistance properties, showing excellent compatibility of the various components at the appropriate component ratios. The multistage heat treatment of embodiment design makes each stage that aerogel chemical structure formed can fully accomplish in each temperature section, has avoided reaction competition each other and too high reaction temperature to the destruction of aerogel chemical structure. The absence of carbon quantum dots in example 2 causes a certain reduction in aerogel performance, especially thermal resistance performance. This shows that carbon quantum dots are bridged to make the aerogel form a multilayer interface, and further enhance the performance of the aerogel through the effects of interface thermal resistance and the like. Examples 3,4, 5 demonstrate different properties of aerogels at different inorganic gel concentrations. Obviously, the inorganic gel can be added into the system to provide certain hydrophobic and thermal resistance performance. However, as shown in example 4, the introduction of excess inorganic gel rather causes a certain reduction in performance, which results from the accumulation of excess inorganic phase such that the reduction of phase interface reduces interfacial effects and microscopic collapse caused by excessive binding force. While, as shown in examples 6, 7, the blind addition and reduction of the content of organic phase resulted in a drastic change in the aerogel properties, illustrating the necessity of a suitable formulation.

Claims (9)

1. An inorganic/organic intermingled hydrophobic polyimide aerogel composite material is characterized in that a polyimide organic gel system and a cobalt iron oxide inorganic gel system are mutually combined by taking modified carbon quantum dots as bridges; the organogel system and the modified inorganic gel system in the composite material are mutually doped and fixed and are jointly used as a framework of the composite material; the thermal decomposition temperature of the composite material is more than or equal to 485 ℃; the water contact angle is 120-135 degrees.
2. A method of preparing an inorganic/organic intermingled hydrophobic polyimide aerogel composite as claimed in claim 1, comprising the steps of:
1) reacting a diamine monomer and a dianhydride monomer in an organic solvent at a low temperature to obtain a polyamic acid solution;
2) reacting the polyamic acid solution with a quaternization reactant, slowly adding the reaction product into deionized water at a low temperature for precipitation, washing with the deionized water until the organic solvent is completely removed, and drying the obtained product to obtain a polyamic acid water-soluble precursor;
3) dissolving the polyamic acid water-soluble precursor in a modified carbon quantum dot/deionized water solution with the mass fraction of 0.5-2.5%, slowly adding the polyamic acid water-soluble precursor into a cobalt-iron oxide inorganic gel liquid phase system in batches, pre-freezing and freeze-drying to obtain a polyamic acid aerogel;
4) and carrying out thermal imidization treatment on the polyamic acid aerogel to obtain the inorganic/organic mutually-doped hydrophobic polyimide aerogel composite material.
3. The production method according to claim 2, wherein the diamine monomer is one or more of 3,4 '-diaminodiphenyl ether, 4' -diaminodiphenyl ether, 2- (4-aminophenyl) -5-aminobenzimidazole, and 2,2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl; the dianhydride monomer is one or more of 1,2,4, 5-pyromellitic dianhydride, 3,3' -biphenyl tetracarboxylic dianhydride, 3,3',4,4' -triphenyl diether tetracarboxylic dianhydride and maleic anhydride; the molar ratio of the total molar amount of the diamine monomer to the total molar amount of the dianhydride monomer is one of 100:101, 50:51 and 20: 21; the organic solvent is one or more of N-methyl pyrrolidone, N-dimethylformamide, N-dimethylacetamide, methanol, dimethylethanolamine and ethanol; the mass ratio of the total mass of the diamine monomer and the dianhydride monomer to the mass of the organic solvent is 1: 8-15; the low-temperature environment is-1-4 ℃.
4. The preparation method according to claim 2, wherein the quaternization reagent is one or more of triethylamine, N-methyldiethanolamine and pyridine; the molar ratio of the molar weight of the quaternization reactant to the molar weight of the dianhydride monomer is 1: 0.5-2; the low-temperature environment is 0-5 ℃; the drying method is freeze drying.
5. The method according to claim 2, wherein the thermal imidization is a multi-stage thermal treatment comprising the steps of:
(1) heating the mixture from room temperature to 75-95 ℃ at a heating rate of 2-5 ℃/min;
(2) heating to 100-120 ℃ at a heating rate of 0.5-3 ℃/min;
(3) preserving the heat for 40-120 minutes at 100-120 ℃;
(4) heating from 100-120 ℃ to 170-210 ℃ at a heating rate of 1-4 ℃/min;
(5) preserving the heat for 60-130 minutes at 170-210 ℃;
(6) heating from 170-210 ℃ to 280-320 ℃ at a heating rate of 1-3 ℃/min;
(7) preserving the heat for 40-80 minutes at 280-320 ℃;
(8) cooling from 280-320 ℃ to room temperature at a cooling rate of 2-4 ℃/min.
6. The preparation method of claim 2, wherein the modified carbon quantum dot is an amino modified carbon quantum dot obtained by reduction and cleavage based on graphene oxide,
the preparation method of the modified carbon quantum dot comprises the following steps:
a) dispersing common graphene oxide in water by ultrasonic, and mutually dissolving the graphene oxide in an amino modifier aqueous solution;
b) placing the graphene oxide/amino modifier water dispersion system in a polytetrafluoroethylene hydrothermal reaction kettle to perform hydrothermal reaction for 4-16 h at a constant temperature;
c) and carrying out suction filtration on the obtained modified carbon quantum dot sol, carrying out heat treatment on the filtrate, dialyzing in a dialysis membrane for 4-7 days, and freeze-drying the product to obtain the amino modified carbon quantum dot.
7. The preparation method according to claim 6, wherein the amino modifier is one or more of ammonia water, ethylenediamine and triethylenetetramine.
8. The preparation method according to claim 6, wherein the hydrothermal reaction temperature is 80 ℃, the heat treatment temperature is 100 ℃, and the time is 1 h.
9. The method of claim 2, wherein the cobalt iron oxide inorganic gel liquid phase system is prepared by the steps of: dissolving ferric chloride and cobalt acetate in deionized water, and gradually adjusting the pH value to 8.5 by using triethylamine to obtain a cobalt-iron oxide inorganic gel liquid-phase system; the mass ratio of the ferric chloride to the cobalt acetate is 1: 2-5, and the mass ratio of the ferric chloride to the cobalt acetate to the deionized water is 1: 20-250.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114536627A (en) * 2022-02-22 2022-05-27 深圳捷智通电缆技术有限公司 Multilayer polyimide film with electromagnetic shielding capability and preparation method thereof
CN115045002A (en) * 2022-05-17 2022-09-13 陕西科技大学 High-temperature-resistant carbon nanotube/polyimide force-sensitive sensing fiber and preparation method thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070259979A1 (en) * 2006-05-03 2007-11-08 Aspen Aerogels, Inc. Organic aerogels reinforced with inorganic aerogel fillers
CN106317407A (en) * 2016-08-23 2017-01-11 北京化工大学 Preparing method of polyimide aerogels and hybrid aerogels thereof
CN108439376A (en) * 2018-03-21 2018-08-24 大连理工大学 A kind of preparation method of the graphene aerogel composite material of carried magnetic nano particle
CN111607228A (en) * 2020-07-10 2020-09-01 四川大学 Polyimide/multiwalled carbon nanotube/nano ferroferric oxide composite aerogel and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070259979A1 (en) * 2006-05-03 2007-11-08 Aspen Aerogels, Inc. Organic aerogels reinforced with inorganic aerogel fillers
CN106317407A (en) * 2016-08-23 2017-01-11 北京化工大学 Preparing method of polyimide aerogels and hybrid aerogels thereof
CN108439376A (en) * 2018-03-21 2018-08-24 大连理工大学 A kind of preparation method of the graphene aerogel composite material of carried magnetic nano particle
CN111607228A (en) * 2020-07-10 2020-09-01 四川大学 Polyimide/multiwalled carbon nanotube/nano ferroferric oxide composite aerogel and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
XINHAI ZHANG, ET AL.: "Double-cross-linking strategy for preparing flexible, robust, and multifunctional polyimide aeroge" *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114536627A (en) * 2022-02-22 2022-05-27 深圳捷智通电缆技术有限公司 Multilayer polyimide film with electromagnetic shielding capability and preparation method thereof
CN114536627B (en) * 2022-02-22 2023-12-22 宜昌予信天诚新材料技术有限公司 Multilayer polyimide film with electromagnetic shielding capability and preparation method thereof
CN115045002A (en) * 2022-05-17 2022-09-13 陕西科技大学 High-temperature-resistant carbon nanotube/polyimide force-sensitive sensing fiber and preparation method thereof
CN115045002B (en) * 2022-05-17 2023-12-29 陕西科技大学 High-temperature-resistant carbon nano tube/polyimide force-sensitive sensing fiber and preparation method thereof

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